Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Kiwi Jasper
A speckled green-and-black stone resembling kiwi fruit, technically a quartz-amazonite aggregate rather than true jasper.
mineral
Banded Iron Formation
Ancient chemically deposited rock of alternating iron-oxide and silica bands recording Earth's early oxygenation and a major iron ore source.
sedimentary
Tourmaline Schist
A foliated schist threaded with black tourmaline (schorl) needles, marking boron-rich metamorphic or metasomatic conditions.
metamorphic
Chevron Amethyst
A naturally banded quartz combining purple amethyst and white quartz in striking V-shaped chevron or zigzag patterns.
crystalSonoran Sunset Jasper
A vivid copper-bearing Mexican stone of red cuprite and green chrysocolla that evokes a desert sunset.
mineral
Grape Agate
Clusters of tiny botryoidal chalcedony spheres resembling bunches of grapes, famously purple, found in Indonesia.
mineral
Hawk's Eye
The blue-grey relative of tiger's eye, a chatoyant quartz showing a shifting band of light like a bird of prey's eye.
gemstone
Prasiolite
A pale green variety of quartz, usually created by heat-treating amethyst, often marketed as green amethyst.
gemstone
Amethyst
The purple variety of quartz, colored by iron and natural irradiation, prized as the classic violet birthstone of February.
crystal
Coquina
A soft, porous limestone made of loosely cemented shell and coral fragments, used as a coastal building stone.
sedimentary
Brown Jasper
An opaque earth-toned jasper colored brown by iron oxides, ranging from pale tan to deep chocolate.
mineral
Deschutes Jasper
A prized Oregon picture jasper from the Deschutes region known for soft scenic landscapes in cream, tan, and blue-gray.
mineral
Graphic Granite
A pegmatitic granite in which quartz and feldspar intergrow to resemble ancient runic or Hebrew script.
igneousFeather Jasper
A jasper marked with soft feather- or plume-like mineral inclusions that drift through a pale silica body.
mineral
Shattuckite
A rare deep-blue copper silicate mineral, often fibrous or massive, named for the Shattuck Mine in Arizona and prized by collectors.
mineralRoyal Imperial Jasper
A premium Mexican imperial jasper showing soft pastel swirls and orbicular eyes in lavender, mint, cream, and rust.
mineralGary Green Jasper
An Oregon jasper, also called larsonite, of silicified fossil wood showing olive-green fields laced with black dendritic patterns.
mineral
Ametrine
A natural bicolor quartz that combines purple amethyst and golden citrine in a single crystal.
crystalRogue River Jasper
An Oregon picture jasper from the Rogue River area showing earthy scenic patterns in tan, brown, gold, and cream.
mineral
Aventurine
A translucent quartz speckled with glittery mineral inclusions that produce a shimmering aventurescence, most often green.
crystal
Pisolite
A sedimentary rock built from pea-sized concentric spheres called pisoids, often carbonate but sometimes iron or aluminum-rich.
sedimentary
Lithic Sandstone
A sandstone in which the dominant grains are fragments of pre-existing rocks rather than single minerals, signaling rapid erosion nearby.
sedimentary
Lapis Lazuli
An intensely blue metamorphic rock of lazurite flecked with golden pyrite, prized for millennia as a gemstone and ultramarine pigment.
metamorphicPantellerite
An iron-rich peralkaline rhyolite, a silica-rich volcanic rock named for the Italian island of Pantelleria.
igneous